ALMA, Ark. (AP) - A grandfather fatally shot his two grandchildren and his daughter's boyfriend Tuesday afternoon in rural Arkansas before turning the gun on himself, sheriff's officials said.

Crawford County Sheriff Ron Brown said Tim Adams shot his 4-month-old grandson, 4-year-old granddaughter and the boyfriend of his daughter at Adams' home near Alma in western Arkansas, The Southwest Times Record newspaper reported. Adams' daughter, who ran from her father as he fired shots, was not wounded. Adams later shot himself in front of a deputy who responded to a call about the shootings, Brown said.

Authorities have not yet determined a motive for the shootings.

Alma is a town of about 5,500 people about 140 miles northwest of Little Rock.

Brown said that when the daughter, boyfriend and two children drove up to the home Tuesday afternoon, Adams came outside carrying a gun. Adams first shot the woman's boyfriend, then the 4-month-old boy, who was in a car seat in the back of the vehicle, Brown said.

The woman grabbed the wounded infant and ran into the home. Adams pursued her, firing shots as she fled with the baby, before he returned to the front yard and shot his 4-year-old granddaughter, Brown said.

Alma police received a call about the shooting around 3 p.m. A sheriff's deputy who responded found a man and 4-year-old girl lifeless in the front yard, Brown told the paper.

"There was a lot of chaos and yelling from the mother of the victims," Brown said.

The deputy went through the house and into the backyard, where he found Adams speaking on the phone with his back to the home. When the deputy spoke to him, Adams turned around with a long gun in his hands and shot himself, Brown said.

Brown, who was an Alma police officer for 15 years, said he has known Adams a long time. Adams operated a roofing business from the residence, which he owned, Brown said.

Brown said he did not know if Adams has an arrest or conviction record.